Nasopharyngeal Carcinoma: a Model Cancer to Understand Tumor Rejection.

Dear Editor, In a recent study published in Proc Natl Acad Sci USA,we demonstrated that the impaired expression of MHC-Ⅰ due to elevated levels of miR-155 contributes to immune evasion in diffuse large B cell lymphoma.1 This research builds on our previous publication,showing that the silencing of ICOSL by miR-155 overexpression,2 combined with the newly identified role of miR-155 in regulating MHC-Ⅰ,are key events in disallowing even large numbers of infiltrating cytotoxic T cells,that we call"frustrated T cells",from eliminating the tumor cells.